Compressor-unloader governor



April 15, 1930. B, s, MKMAN 1,754,218

COMPRESSOR UNLOADER GOVERNOR Filed May 51, 1928 INVENTOR BURTON S. NKMANBYWW ' ATTQ EY l rl application filed May 31,

This invention relates to fluid compressors and more particularly to agovernor device for controlling the loading and unloading of thecompressor,

a The principal object of my invention is to provide an improvedcompressor unloader governor, which is simple in construction and whichcan be cheaply manufactured.

Tn the accompanying drawing, the single figure is a diagrammatic view,partly in section, oil a portion oil a fluid compressor and havingassociated therewith an unloading means and a compressor unloadergovernor constructed in accordance with my invention.

The construction shown in the drawing comprises a fluid compressorcylinder 1, shown in part, and having a cylinder head 2 provided with avalvechamber 3, containing the usual discharge valve 4L, for controlaling communication from the fluid compres sor 1 to the usual storagereservoir 5.

An unloading valve 6 controls communication ifrcm the compressingcylinder to an atmospheric port 7 and is provided with an operating stem6. Carried at the outer end of the stem 3 is a member 9 which is subjectto the pressure at a coil spring 10 acting through the stem 3 to urgethe valve 6 to. its seat. i

Pivotally mounted on a pivot pin ll car ried by the head 2 is a lever 12having a long arm 13 provided with an adjustable screw 14 adapted toengage the end of the valve stem 8. A spring 15 interposed between thecylinder head 2 and the arm 13 urges the arm away from the stem 8.

Tht short arms 16 ot the lever 12 carries an adjustable screw 17 towhich the movement of a flexible diaphragm 18 is transmitted an througha ball 19. The chamber 20 at one side of the diaphragm 18 is connectedto a pipe 21 which leads to my improved governor device 22.

The governor device 22 comprises a casting 23 which is mounted in acasing 2d and lit CUMPHIlEflSUIEt-UNLQADER RGi-UVEENUR mounted in acavity in the casting is a double beat piston head 25 having valves 26and 27. A Bourdon tube 28 is mounted in the casing 24 and has one endsecured in the casting 23 in a member 34, secured to the free end of sthe Bourdon tube 28. The screw 36 is provided with a head 32 and ismaintained in its position of adjustment by a loclr nut 33..

Assuming that the screw 36 has been adjusted tor the pressure at whichit is desired to unload the compressor, at all pressures below thispressure, the spring action oi the tube will exert a downward pressureon stem 31 to hold the valve 27 seated against the pressure in pipe 30..

When the pressure in pipe 30 has increased to a point where the internalressure in the tube 28 plus the pressure actin on the enposed area oithe valve 27 ercee s the spring action of the tube 28, the valve 2'?will be slightly lifted from its seat, permitting leahage of fluid frompipe 30 to the space below the piston head 25,

The pressure of fluid from pipe 30 will then act on the tull area ofpiston head 25, so

as to cause a quick upward movement thereof and thereby causing thevalve 26 to seat.

lit will be noted that the area oii the valve 26 is greater than that ofthe valve 27, so that although the spring action of the tube23 isincreased by its upward movement, the fluid pressure acting on thepiston head 25 will be sutflcient to hold the valve 26 seated.

on valve 27 is unseated, fluid under pressure is supplied from thereservoir 5 through pi e 30 to pipe 21, by leakage past the piston ead25, and thence to diaphragm chamber 18. The diaphra m 18 is then movedupwardly, so that the ever 12 is actulid 5 operates without compressingfluid into the "reservoir 5.

' When the fluid pressure in the reservoir 5 has fallen sufiiciently topermit the spring action of the tube 28 to overcome the pressure 10 offluid acting on the under side of the piston head 25, the valve 26 willbe slightly lifted from its seat and leakage of fluid from pipe 30, pastthe piston head 25, to the chamber above the piston head will occur.

The area of the exhaust port 35 is so restricted that the pressure abovethe piston head'25 will build up sufficiently to permit the springaction of the'tube 28 to quickly shift the piston head so as to causethe valve 27 to seat.

With valve 26 unseated, fluid is vented from diaphragm chamber 20through ipe 21 to the atmosphere, by way of port 3 so that the pressureof s ring 15' acts to shift the arm 13 upwardly, t hereby permitting thevalve 6 to seat. The compressor then operates to compress fluid into thereservoir 5. 1

While one illustrative embodiment of the invention has been described indetail, it is not my intention to limit its scope to that emb0.di mentor otherwise than by the terms of the appended claims. I

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1.- The combination with a fluid compressor unloading device having amovable abutment operated by an increase in fluid under pressure forunloading the compressor, of a governor comprising a Bourdon tubesubject to the pressure of fluid compressed by the compressor, valvemeans for controlling the fluid pressure on said abutment, and a membercarried by said tube for engaging said valve means, the resiliency ofthe tube urging said valve means in one direction and the expansion ofthe tube by fluid under pressure urging 'said member away from saidvalve means. I

2. The combination with an unloading device for a fluid compressoroperable by variations in fluid under pressure, of a governor device forcontrolling the fluidpressure for operating said unloading devicecomprising a Bourdon tube subject to the pressure of fluid compressed bythe compressor, valve means for controlling. the fluid pressure on saidunloadin device and having a valve stem, and a mem er carried by saidtube for engaging ,0 said stem, the tube being under initial tension tourge the valve means in one direction,

and the expansion of. the tube by fluid under pressure urging saidmember away from said valve stem.

3. The combinationwith an unloading de-.

vice for a fluid compressor operable by variations in fluid underpressure, of a governor devicefor controlling the fluid pressure foroperating said unloading device comprising a Bourdon tube subject to thepressure of fluid compressed by the compressor, a double 1 beat valvedevice for controlling the supply and release of fluid under pressure toand from said unloading device and having a. valve stem, and a membercarried by said tube for engaging said stem, the resiliency of the tubeitself being utilized to urge said member into engagement with saidvalve stem for operating said valve device to release fluid underpressure from said unloading device.

4. The combination with an unloading device for a fluid compressoroperable by variations in fluid under pressure of a governor device forcontrolling the fluid pressure for operatin said unloading devicecomprising a Bour on tube subject to the pressure of fluid compressed bythe compressor, a valve forsupplyingfluid under pressure to saidunloading device, a valve for venting fluid from said unloading device,astem for operatin said valves, and a member carried by sai tube forengaging said stem, the stem being operated by the resiliency of thetube for seating one valve and the expansion of the tube by fluid underpressure urging said member away from said stem. 5. The combination withan unloading-device for a fluid compressor operable by variations influid under pressure, of a governor device for controllin the fluidpressure for operating said unloa ing device comprising a Bourdon tubesubject to the pressure of fluid compressed ,by the compressor, a valvefor supplying fluid under pressure to said unloading device, a valve forventing fluid from said unloading device, a stem for operating saidvalves, a member carried by said tube, and an adjustable screw mountedin said member for o crating said stem.

6. The com ination with an unloading device for a fluid compressoroperable by varia- -tions in fluid under pressure, of a governor devicefor controlling the fluid pressure for operating said unloading devicecomprising a Bourdon tube subject to the pressure of fluid compressed bythe compressor, valves for controlling thesupply of fluid under pressureto and its exhaust from said unloading device, a stem for operating saidvalves means carried by said tube for en aging said stem, and a pistonhead carried y said stem and subject to fluid pressure compressed b thecompressor, the stem and said valves eing operated by said means in onedirection, and fluid under pressure on said piston urging said valves inthe opposite direction.

7. The combination with an unloading device for a fluid compressoroperable by variations in fluid under pressure, of a governor device forcontrolling the fluid pressure for operating said unloading devicecomprising a lBourdon tube subject to the pressure of fluid compressedby the compressor, a valve for supplying fluid under pressure to said unloading device, a stem operated by said tube for operating said valve,and a piston head carried by said stem and exposed to fluid compressedby the compressor When said valve is lifted from its seat.

In testimony whereof I have hereunto set my hand, this 23rd day of May,192&

v BURTON S. AIRMAN

